Extreme isotopic heterogeneity in Samoan clinopyroxenes constrains sediment recycling.

ABSTRACT: Lavas erupted at hotspot volcanoes provide evidence of mantle heterogeneity. Samoan Island lavas with high ⁸⁷Sr/⁸⁶Sr (>0.706) typify a mantle source incorporating ancient subducted sediments. To further characterize this source, we target a single high ⁸⁷Sr/⁸⁶Sr lava from Savai'i Island, Samoa for detailed analyses of ⁸⁷Sr/⁸⁶Sr and ¹⁴³Nd/¹⁴⁴Nd isotopes and major and trace elements on individual magmatic clinopyroxenes. We show the clinopyroxenes exhibit a remarkable range of ⁸⁷Sr/⁸⁶Sr-including the highest observed in an oceanic hotspot lava-encompassing ~30% of the oceanic mantle's total variability. These new isotopic data, data from other Samoan lavas, and magma mixing calculati

SUBMITTER: Adams JV 

PROVIDER: S-EPMC7902626 | biostudies-literature | 2021 Feb

REPOSITORIES: biostudies-literature